Computers and many other products have several electrical connectors for operatively coupling internal and external components to one another. In a computer, for example, disk drives and CD-ROMs are coupled to a motherboard using internal connectors, and external output devices (e.g., printers and displays) are coupled to the computer using external connectors. The electronics industry typically uses standardized connectors so that manufacturers can purchase standard connectors from several different outside vendors.
Each computer generally has a plurality of different multiple-pin connectors. Among the more popular multiple-pin connectors available for assembling computers are the D-type, rectangular connectors, and center ribbon cable connectors. Additionally, card-edge connectors having 15–100 pins are also available to connect printed circuit boards to motherboards or other devices. One concern of electrical connectors is maintaining electrical contact between the electrical connectors and the receptacles with which they are engaged. Several types of electrical connectors rely on friction between the connector pins and mating sockets to hold the electrical connectors in the receptacles. Other types of electrical connectors have positive retention devices that securely attach the electrical connectors to the receptacles.
FIGS. 1A and 1B are partial isometric views of two positive retention devices that are commonly used to prevent a connector from disengaging a socket. FIG. 1A, more specifically, shows a D-type connector 110 with two thumbscrews 112 that thread into holes 113 in a receptacle 111. FIG. 1B shows a rectangular type connector 120 with wire-clip latches 122 that snap into slots 123 in a receptacle 121. Not shown in FIG. 1 is a common card-edge type connector used to attach a printed circuit card to a motherboard. This type of connector is commonly provided with lugs that can be soldered to the motherboard to prevent disengagement of the circuit card.
Not all electrical connectors, however, are provided with positive retention devices. For example, electrical connectors for center ribbon cables that are used with drive devices (e.g., floppy disk or CD-ROM drives) typically do not have positive retention devices and rely only on pin friction to maintain engagement with the drive devices. A common problem encountered with this type of connector is that vibrations during transport or handling can cause the connector to disengage from its receptacle. Disengagement can occur during shipment from the point of assembly to the point of sale, or during typical use by the purchaser. This problem is especially acute with portable laptop computers.
FIG. 2 is a partial isometric view of a standard 68-pin IDE (integrated drive electronics) center ribbon cable connector 210 that does not have one of the positive retention devices more commonly used with the D-type or rectangular type connectors shown in FIG. 1. The center ribbon cable connector 210 mates with a 68-pin SCSI (small computer systems interface) connector receptacle 211 to connect an ultra-wide SCSI ribbon cable 215 to a 3½-inch drive device 230. Without a positive retention device, the center ribbon cable connector 210 is prone to vibrate out of the 68-pin SCSI connector receptacle 211 during shipment of a computer 200.